Antigen detection of Trichinella

ABSTRACT

Trichinella can be detected in a tissue extract sample. A suitable kit includes (a) a detection carrier containing a first antibody against one or more antigens of Trichinella, and (b) (i) a second antibody against one or more antigens of Trichinella, wherein the second antibody is bound to a signal molecule, or (b) (ii) contains one or more antigens of Trichinella bound to a signal molecule, wherein the antigens of (b) (ii) are configured so as to dissolve binding of the antigens of (a) to the first antibody by competitive displacement.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to European patent applicationsEP 17 208 994.8 filed Dec. 20, 2017 and EP 18 199 404.7 filed Oct. 9,2018, the content of each of which is incorporated by reference in itsentirety.

REFERENCE TO A SEQUENCE LISTING

The instant application contains a Sequence Listing which has been filedelectronically in ASCII format and is hereby incorporated by referencein its entirety. Said ASCII copy, created on Dec. 18, 2018, is named181203_Sequence_Listing-as-filed.txt and is 6,692 bytes in size.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention is directed at a method of detecting Trichinellain a tissue extract sample, the use of a detection system according tothe invention for detection of Trichinella, and a kit comprising (a) adetection carrier comprising a first antibody against one or moreantigens of Trichinella, and (b) (i) a second antibody against one ormore antigens of Trichinella, wherein the second antibody is bound to asignal molecule, or (b) (ii) comprises one or more antigens ofTrichinella bound to a signal molecule, wherein the antigens of (b) (ii)are configured so as to dissolve binding of the antigens of (a) to thefirst antibody by competitive displacement.

Description of Related Art

Trichinella spiralis (T. spiralis) is a nematode of the genusTrichinella and can cause serious human diseases. So-calledtrichinellosis is caused by the consumption of raw or insufficientlyheated meat, which is infected with Trichinella. Symptoms of thisdisease are initially nausea, diarrhea and muscle pain. As the diseaseprogresses, paralysis, facial swelling—especially periorbital—,conjunctivitis, headache, rash, and myocarditis are added, among otherthings [1].

Generally, the parasite is transmitted by the meat of various mammalssuch as domestic pigs, horses, bears, wild boars or rodents. Elevendifferent species of the genus Trichinella are known, which can bedivided into two groups: species such as T. spiralis, which form acollagen capsule in the muscle cell of the host organism, by which theyare permanently encapsulated, and species that do not form a capsule,such as T. pseudospiralis [2].

With few exceptions, T. spiralis is climate-dependent and occursworldwide. In the European Union (EU), there are rarely cases oftrichinellosis in domestic swine derived from commercial breeding andfattening farms, but the prevalence is clearly higher in the case ofwild animals such as wild boars, foxes, and raccoon dogs or privatelykept pigs. In China, the prevalence in pigs is generally up to 4%.There, over 500 outbreaks occurred between 1964 and 2002, with a totalof over 25,000 sick persons [3].

The life cycle of T. spiralis is widely known. After oral ingestion offoods infected with T. spiralis, the larvae are released into the smallintestine after approximately 24 h, due to the collagen capsule beingdecomposed by the digestive fluid. Over four molts, the larva developsinto an adult form, and fertilization of the females occurs. After 5-10days, new larvae are born (NBL—New Born Larvae) that spread through theblood and lymphatic system. 6-12 days later, the larvae invade thestriated musculature (ML—muscle larvae), and after 4-6 weeks, capsuleformation begins, with the capsule increasingly calcifying over time.Over years to decades, a metabolic exchange with the tissue takes place[4].

To survive for years in the host's muscles, T. spiralis manipulates thehost immune system with the help of numerous proteins that are secretedinto the surrounding tissue. The so-called excretory and secretoryproteins (E/S proteins) are predominantly secreted by the stichosome,which consists of about 50 large glandular cells, the stichocytes, andis located in the esophageal wall.

Trichina examination, formerly called Trichina inspection, is anexamination of meat from food-producing animals for T. spiralis afterslaughter. It is part of the official inspection before slaughter andafter slaughter of slaughter animals subject to examination, and wasintroduced because of several epidemics that occurred in the middle ofthe 19th century. Thus, the obligatory Trichina inspection wasintroduced in the Kingdom of Prussia as early as 1866. If the meat is tobe released for human consumption, all animals within the EU which maybe carriers of T. spiralis, e.g. domestic pigs, horses, bears or wildboars must be examined (EC No. 2015/1375).

The costs of the Trichina examination are €0.12 to €3.70 per pig,depending on the size of the slaughterhouse and the associated amount ofslaughtered animals [5].

Serology is not useful in the Trichina examination, as seroconversiontakes place at an infectious dose of 20,000 larvae after 3-4 weeks andof 100 larvae after 5-7 weeks [6].

There are several detection systems for the detection of T. spiralis intissue, which are permissible according to EU Regulation (EC No.2015/1375), and are used in slaughterhouses or in the laboratory. Inaddition to the mechanically assisted method of artificial digestionwith the Stomacher Lab-blender 3500, the automatic digestive process forbulk samples up to 35 g with the Trichomatic-35®-Mixer and the test byartificial digestion using the PrioCHECK® Trichinella AAD Kit, there aretwo other methods, namely the magnetic stirring method for artificialdigestion of bulk samples, and the “on-filter isolation” technique withlarva detection by means of a latex agglutination test (Trichin-Lantigen test kit from Bio-Rad). In this context, it should be noted thatthe most commonly performed method, simultaneously considered to be areference, is the magnetic stirring method for artificial digestion. Thelatest method is the magnetic stirring method for artificial digestionof bulk samples with subsequent “on-filter-isolation” technique andlarva detection by means of a latex agglutination test.

The magnetic stirring method for artificial digestion of bulk samples issufficiently known to a person skilled in the art [7]. This method hasnumerous disadvantages, such as varying quality of the pepsin used,temperature and time sensitivity (digestion should take place for 30minutes at 46° C. to 48° C.), great time intensity (due to the digestionprocess, sedimentation steps, equipment cleaning and microscopy), manualevaluation by specially trained personnel, difficult and sometimesdangerous handling of individual steps due to working with hydrochloricacid, for example, difficult evaluation (for example, the digestivefluid may have been washed insufficiently and the larvae may thus beoverlooked due to the excessive turbidity), and the risk ofcontamination due to poorly cleaned equipment.

Also, the “on-filter-isolation” technique and subsequent larva detectionby means of the latex agglutination test Trichin-L has numerousdisadvantages. For example, the method mentioned here also has theabove-mentioned disadvantages in terms of digestion, since the digestionstep is identical. Furthermore, the sensitivity of the test can beseverely impaired due to chemical products such as detergents incleaning solutions. In addition, there are many devices that requirethorough cleaning, and therefore the risk of contamination is quitehigh.

Therefore, there is a need for a method which, by being easy to handle,provides fast, inexpensive and above all reliable Trichinella detectionin animal tissue, especially muscle tissue.

BRIEF SUMMARY OF THE INVENTION

Methods, uses, and kits that allow rapid, inexpensive, and reliableTrichinella detection in tissue are described below and are the subjectof the described invention.

Embodiments of the present invention include the following:

1. A method of detecting Trichinella in a tissue extract sample, wherein90% of the particles in the tissue extract sample have a diameter of 300μm or less (D90≤300 μm).

2. The method according to 1, wherein the tissue extract sample is amammalian sample, preferably a sample from a pig.

3. The method according to one of 1 or 2, wherein 90% of the particlesin the tissue extract sample have a diameter of 250 μm or less (D90≤250μm), preferably 200 μm or less (D90≤200 μm).

4. The method according to one of 1 to 3, wherein the tissue extractsample is from musculature.

5. The method according to one of 1 to 4, wherein in the preparation ofthe tissue extract sample

(a) a temperature of 45° C., preferably 40° C., is not exceeded; and/or

(b) no enzymatic and/or chemical cleavage of the tissue takes place.

6. The method according to one of 1 to 5, wherein the method

(a) does not comprise a microscopy step;

(b) is used in meat inspection; and/or

(c) has a detection limit of s 7 ng antigen per ml of tissue extract.

7. The method according to one of 1 to 6, wherein the method isperformed by means of an immunoassay, preferably by means of an ELISA,lateral flow assay, line blot assay, Western blot assay, bead-basedassay, vertical filtration assay or 3D immunofiltration assay.

8. The method according to one of 1 to 7, wherein Trichinella isTrichinella spiralis.

9. Use of a detection system for the detection of Trichinella,preferably for meat inspection, wherein the detection system

(a) comprises a detection carrier comprising a first antibody againstone or more antigens of Trichinella, and

(b) (i) comprises a second antibody against one or more antigens ofTrichinella,

wherein the second antibody is bound to a signal molecule, or

(b) (ii) comprises one or more antigens of Trichinella bound to a signalmolecule, wherein the antigens of (b) (ii) are configured so as todissolve binding of the antigens of (a) to the first antibody by meansof competitive displacement.

10. Kit comprising

(a) a detection carrier comprising a first antibody against one or moreantigens of Trichinella, and

(b) (i) a second antibody against one or more antigens of Trichinella,wherein the second antibody is bound to a signal molecule, or

(b) (ii) comprises one or more antigens of Trichinella bound to a signalmolecule, wherein the antigens of (b) (ii) are configured so as todissolve binding of the antigens of (a) to the first antibody by meansof competitive displacement.

11. The kit according to 10, wherein the kit further comprises adescription of a method according to one of 1 to 8.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows the E/S proteins of an encapsulated Trichinella spiralislarva. The E/S proteins are secreted by the larva into the capsule andinto the surrounding tissue. By comminuting the tissue, the proteins arereleased into the sample material.

FIG. 2 shows an incubation schematic of the Trichinella antigen captureELISA. 1) Anti-Trichinella Ab C9 immobilized on a microtiter plate, 2)sample (Trichinella antigen), 3) Biotinylated detection Ab B7 bound tostreptavidin with PolyHRP80.

FIG. 3 shows the particle size determination of pork shredded using theGM200 knife mill from Retsch. 100×1 g of diaphragm muscle werecomminuted with 200 ml of PBS in the GM200 at 10,000 rpm for 6 and 9min, respectively. The particle size is plotted against Q3 [%] (volumepercent). In each case, about 60 million particles were measured. A)Particle size determination using the Camsizer® XT. n=0.3 B) Particlesize determination using the HORIBA LA-960. n=1.

FIG. 4 shows a recorded image of individual meat particles during themeasurement using the Camsizer® XT. The shape is generally not round,but rather very fibrous and elongated, so that the width to length ratiodecreases.

FIG. 5 shows the test of the antibodies anti-[TRISP][B7] andanti-[TRISP][C9] for the detection of Trichinella. A)-D) T. spiralisIIFT (Indirect Immunofluorescence Test): Ab B7 and Ab C9 were incubatedat a concentration of 2 μg/ml. A)+B) Incubation with Ab B7: The Ab showsa clear reaction both in the case of the encapsulated Trichinella larvain cross-section and in the case of the muscle larva; C)+D) Incubationwith Ab C9: Like B7, the Ab shows a clear reaction both in the case ofthe encapsulated Trichinella larva in cross section and in the case ofthe muscle larva; E) Western blot: 5 μg of T. spiralis lysate areapplied in each case, and the incubation was carried out with the Ab B7and the Ab C9 (concentration 0.4 μg/ml).

FIG. 6 shows the test of the specificity of the antibodiesanti-TRISP[B7] and anti-TRISP[C9] by means of Western blot. Track 1)Trypanosoma cruzi, 2) Ascaris suum, 3) Strongyloides ratti, 4) Toxocaracati, 5) Toxoplasma gondii, 6) Salmonella typhimurium, 7) Salmonellacholerasuis strain A, 8) Salmonella cholerasuis strain B, 9) Salmonellatyphisuis, 10) Trichuris suis, 11) Trichinella spiralis. Applied: 5 μglysate each. Incubation with Ab B7 (concentration 0.4 μg/ml, 2 h).

FIG. 7 shows results of the T. spiralis antigen capture ELISA. A)Detection limit of the T. spiralis antigen capture ELISA. Variousconcentrations of E/S antigen are plotted against the O.D. B) T.spiralis antigen capture ELISA with E/S antigen, positive and negativetissue extract as the sample material. The positive tissue extractsample contained approximately 100 encapsulated Trichinella larvae.Dashed line: Cut-off.

FIG. 8 shows results of the T. spiralis antigen capture ELISA withpositive and negative tissue extract as the sample material. Thepositive tissue extract contained approximately 100 encapsulatedTrichinella larvae. The sample material was comminuted for 3, 6, and 9min. Dashed line: Cut-off. n=3.

FIG. 9 shows an incubation schematic of the manually incubatedTrichinella chemiluminescence immunoassay. 1) Anti-Trichinella captureAb 18H1 immobilized on a magnetic bead, 2) Sample (Trichinella antigen),3) Biotinylated anti-Trichinella detection Ab B7, 4)extravidin/acridinium reagent.

FIG. 10 shows the processing schematic of the chemiluminescence analyzerdevice for the automated Trichinella chemiluminescence immunoassay. Themagnetic bar transports the beads immobilized with anti-Trichinella Ab18H1 successively into reaction vessels filled with various reagents.The sample and trigger B are added automatically.

FIG. 11 shows results of the automated Trichinella chemiluminescenceimmunoassay. The particle sizes of the comminuted pork were measuredafter 2, 3, 5, and 7 min using the particle size analyzer LA-960 fromHORIBA. In addition, meat samples—negative and mixed with 6, 13, and 30Trichinella larvae—were comminuted between 2 and 7 min. The resultingtissue extract was incubated using the automated CLIA. The results aregiven in relative light units (RLU).

DETAILED DESCRIPTION OF THE INVENTION

The inventors of the present invention have surprisingly found thatTrichinella detection can be achieved by immunoassay by means of(mechanical) comminution of Trichinella-infected tissue.

Such an assay allows the detection of ≤7 ng Trichinella antigen per mlof tissue extract or less. In particular, it was possible to show thatas soon as 90% of the particles contained in the tissue extract samplehave a diameter of 300 μm or less (D90≤300 μm), efficient detection ofTrichinella can take place.

In a first aspect, therefore, the present invention is directed at amethod of detecting Trichinella in a tissue extract sample, wherein 90%of the particles in the tissue extract sample have a diameter of 300 μmor less (D90≤300 μm). Trichinella is preferably detected by immunoassay,by detecting an antigen of Trichinella, preferably an antigen specificfor Trichinella in the tissue extract sample.

In preferred embodiments of the invention, the tissue extract sample isa mammalian sample, preferably a sample from a pig.

In preferred embodiments, in the tissue extract sample 90% of theparticles have a diameter of 100 μm or less (D90≤100 μm), preferably 20μm or less (D90≤20 μm).

In other preferred embodiments, the tissue extract sample is derivedfrom musculature.

In preferred embodiments of the method according to the invention, (a) atemperature of 45° C., preferably 40° C., is not exceeded in thepreparation of the tissue extract sample and/or (b) there is noenzymatic and/or chemical cleavage of the tissue.

Furthermore, in preferred embodiments (a), the method does not comprisea microscopy step; (b) use in the context of meat inspection and/or (c)has a detection limit of ≤7 ng antigen per ml of tissue extract.

In further preferred embodiments, the method of the invention isperformed by means of an immunoassay, more preferably by means of anELISA, line blot assay, Western blot assay, bead-based assay, lateralflow assay, vertical filtration assay, or 3D immunofiltration assay.

In preferred embodiments, Trichinella is Trichinella spiralis.

In a second aspect, the present invention is directed at use of adetection system for the detection of Trichinella, preferably in thecontext of meat inspection, wherein the detection system comprises (a) adetection carrier comprising a first antibody against one or moreantigens of Trichinella, and (b) (i) a second antibody against one ormore antigens of Trichinella, wherein the second antibody is bound to asignal molecule, or (b) (ii) comprises one or more antigens ofTrichinella that are bound to a signal molecule, wherein the antigens of(b) (ii) are configured in such a manner that they dissolve binding ofthe antigens of (a) to the first antibody by competitive displacement.

In a third aspect, the present invention is directed at a kit comprising(a) a detection carrier comprising a first antibody against one or moreantigens of Trichinella, and (b) (i) a second antibody against one ormore antigens of Trichinella, wherein the second antibody is bound to asignal molecule, or (b) (ii) comprises one or more antigens ofTrichinella bound to a signal molecule, wherein the antigens of (b) (ii)are configured so as to dissolve binding of the antigens from (a) to thefirst antibody by competitive displacement.

In a preferred embodiment, the kit further includes a description of amethod according to the invention for detecting Trichinella.

As already described, the first aspect of the present invention isdirected at a method of detecting Trichinella in a tissue extractsample, wherein 90% of the particles in the tissue extract sample have adiameter of 300 μm or less (D90≤300 μm).

The term “detection” or “detecting” as used equivalently hereindescribes the qualitative or quantitative determination of Trichinella.Qualitative determination means that only the presence or absence ofTrichinella is determined. Quantitative determination refers todetermination of the relative or absolute amount of Trichinella in asample.

The term “Trichinella” or “trichinae” as used equivalently herein refersto a genus of nematode worms (strain Nematoda) with a parasiticlifestyle. Mammals, and therefore humans, and birds serve asintermediate and final hosts. The main carriers to humans are infectedpigs or their raw meat, for example consumed as ground pork, orinsufficiently cooked meat. Taxonomically, trichinae are classified asfollows: Strain: nematodes (Nematoda); Class: Adenophorea (Adenophorea);Subclass: Enoplea (Enoplea); Order: Trichocephalida; Family:Trichinellidae; Genus: Trichinella. In preferred embodiments of theinvention, Trichinella is selected from the group consisting ofTrichinella spiralis, Trichinella nativa, Trichinella britovi,Trichinella murrelli, Trichinella T6, Trichinella T7, Trichinellanelsoni, Trichinella T8, Trichinella T9, Trichinella pseudospiralis,Trichinella papuae, and Trichinella zimbabwensis. In further preferredembodiments, the Trichinella species is an organism that forms acollagen capsule in a muscle cell of the host organism and ispermanently encapsulated by it. In a still further preferred embodiment,Trichinella is Trichinella spiralis. Trichinella spiralis is a nematodeand, in Central Europe, the most important representative of trichinae.It occurs worldwide, but it does not have much significance in tropicalregions. T. spiralis causes the clinical picture of trichinellosis.

The term “tissue extract sample” as used herein refers to a mixture ofvarious substances of biological origin. The material of biologicalorigin may be epithelial tissue (cell layers covering all internal andexternal surfaces), connective and supporting tissue (tissue thatprovides structural cohesion and fills spaces), specialized tissue (suchas blood, free cells, etc.), muscle tissue (cells that are specializedfor active movement by contractile filaments), nerve tissue (cells thatmake up the brain, spinal cord, and peripheral nerves), and tissuefluid, such as the lymph system. More preferably, the tissue is muscletissue. The muscle tissue may be smooth musculature, cardiac musculatureand/or skeletal musculature. In further preferred embodiments, thesample is taken from the diaphragm, tongue or intercostal muscles of thesubject to be examined. Preferably, the tissue is a solid tissue.

A tissue extract sample can be either heterogeneous or homogeneous. Aheterogeneous tissue extract sample includes tissues of various tissuetypes. A homogeneous tissue extract sample comprises only a giventissue. A homogeneous tissue extract sample is preferred. In alternativeembodiments, the sample is a pooled sample, i.e. the sample materialcomes from different individuals. Or the sample comes exclusively from asingle individual.

The extract can be obtained from pieces of tissue or viable cells. Theseare comminuted and mixed with an aqueous solution, such as buffersolutions, H₂O, cell media and mixtures thereof. Preferably, themanufacturing process does not involve cell cultivation.

In preferred embodiments of the invention, the tissue extract sample isa mammalian sample. In further preferred embodiments, the sample is frompigs, horses, bears, cats, dogs, rodents or humans. Even morepreferably, the sample comes from a domestic pig (Sus scrofadomesticus), a wild boar (Sus scrofa), Pomeranian pig (Sus salvanius),bearded pig (Sus barbatus), Palawan bearded pig (Sus ahoenobarbus),Annamite pustule pig (Sus bucculentus), Visayas pustule pig (Suscebifrons), Sulawesi pustule pig (Sus celebensis), Mindoro pustule pig(Sus oliveri), Philippine pustule pig (Sus philippensis), Javanesepustule pig (Sus verrucosus) or Bawean pustule pig (Sus blouchi).

The term “particle diameter” as used herein refers to a volumetric orlength measurement of the particles being examined in the tissueextract. The particles studied may have a roughly roundish shape or anelongated fibrous structure. In preferred embodiments, 90% of theparticles in the tissue extract sample have a diameter of 300 μm or less(D90≤300 μm), 290 μm or less (D90≤290 μm), 280 μm or less (D90≤280 μm),270 μm or less (D90≤270 μm), 260 μm or less (D90≤260 μm), 250 μm or less(D90≤250 μm), 240 μm or less (D90≤240 μm), 230 μm or less (D90≤230 μm),220 μm or less (D90≤220 μm), 210 μm or less (D90≤210 μm), 200 μm or less(D90≤200 μm), 190 μm or less (D90≤190 μm), 180 μm or less (D90≤180 μm),170 μm or less (D90≤170 μm), 160 μm or less (D90≤160 μm), 150 μm or less(D90≤150 μm), 140 μm or less (D90≤140 μm), 130 μm or less (D90≤130 μm),120 μm or less (D90≤120 μm), 110 μm or less (D90≤110 μm), 100 μm or less(D90≤100 μm), 95 μm or less (D90≤95 μm), 90 μm or less (D90≤90 μm), 85μm or less (D90≤85 μm), 80 μm or less (D90≤80 μm), 75 μm or less (D90≤75μm), 70 μm or less (D90≤70 μm), 65 μm or less (D90≤65 μm), 60 μm or less(D90≤60 μm), 55 μm or less (D90≤55 μm), 50 μm or less (D90≤50 μm), 45 μmor less (D90≤45 μm), 40 μm or less (D90≤40 μm), 35 μm or less (D90≤35μm), 30 μm or less (D90≤30 μm), 25 μm or less (D90≤25 μm), 20 μm or less(D90≤20 μm), 17 μm or less (D90≤17 μm), 15 μm or less (D90≤15 μm), 13 μmor less (D90≤13 μm), 10 μm or less (D90≤10 μm), 8 μm or less (D90≤8 μm)or 6 μm or less (D90≤6 μm).

The particle diameter measurement may take place by devices usingdynamic image analysis (e.g., Camsizer® XT from Retsch) or devices basedon the principle of static laser scattering (e.g., LA-960 from HORIBA).The particle size can be measured in x_(c min) and is defined inaccordance with DIN 66141 as follows: Shortest particle diameter of themeasurements of the maximum diameters within a particle projection(English: particle diameter which is the shortest chord of the measuredset of maximum chords of a particle projection) [10]. Alternatively, theparticle size can be measured using the Feret diameter (x_(Fe)). TheFeret diameter is a measure of the object size along a particulardirection. In general, it can be defined as the distance between the twoparallel planes that constrain the object perpendicular to thatdirection. It is therefore also called the caliber diameter, based onthe measurement of the object size with a caliper. When analyzingparticle sizes, for example in microscopy, where the Feret diameter isapplied to projections of a three-dimensional (3D) object on a 2D plane,this is defined as the distance between two parallel tangential linesinstead of two planes. For a convex particle, the mean Feret diameter(mean of all directions) is equal to the diameter of a circle of equalcircumference. The maximum Feret diameter is the longest Feret diameterwithin the measured set of Feret diameters. The minimum Feret diameteris the shortest Feret diameter within the measured set of Feretdiameters.

Alternatively, the diameter refers to an average diameter, wherein thesum of the diameter measurements of all measured measurable particles isdivided by the total number of particles measured. In anotheralternative embodiment, the diameter, when used in relation to the sizeof the particles, may refer to “D50” such that about 50% of allparticles measured have a particle diameter smaller than the definedmean particle diameter value, and that about 50% of all measurableparticles measured have a particle diameter larger than the defined meanparticle diameter value.

In preferred embodiments of the method according to the invention, inthe preparation of the tissue extract sample (a) a temperature of 100°C., 90° C., 80° C., 70° C., 60° C., 55° C., 50° C., 45° C., 44° C., 43°C., 42° C., 41° C., 40° C., 39° C. or 38° C. and/or (b) there is noenzymatic and/or chemical cleavage of the tissue.

The term “preparation of the tissue extract sample” as used hereinrefers to a multi-step process wherein a tissue sample is taken from anorganism to be examined, this tissue sample (mechanically) minced, andthe minced tissue sample treated by filtration and/or centrifugation.Subsequently, the antigen detection can be carried out in the processaccording to the invention.

The comminution of the tissue sample is preferably carried out purelymechanically, i.e., for example, no enzymatic and/or chemical cleavageof the tissue. Mechanical comminution can take place by cutting, rippingor crushing, but is preferably achieved by cutting (for example via aknife mill). By comminution of the tissue sample, Trichinella larvaealso located in the tissue sample are comminuted. The comminutedTrichinella larvae have a size corresponding to the comminuted tissueafter comminution.

In a preferred embodiment, the term “no enzymatic cleavage” as usedherein refers to the fact that no enzymes are used to comminute thetissue sample. In particular, no proteases (e.g., pepsin), lipases,amylases, cutinases, cellulases, or hemicellulases are used to comminutethe tissue sample.

In a preferred embodiment, the term “no chemical cleavage” as usedherein refers to the fact that no chemical substances such as acids,bases, oxidants, etc. are used to comminute the tissue sample.

Furthermore, in preferred embodiments (a), the method does not comprisea microscopy step; (b) use in meat inspection and/or (c) has a detectionlimit of <20 ng, <15 ng, <10 ng, <9 ng, <8 ng, <7 ng, <6 ng, <5 ng, <4ng, <3 ng, <2 ng, <1 ng, <0.5 ng, <0.25 ng, <0.1 ng, <0.05 ng, <0.01 ng,<0.005 ng or <0.001 ng of antigen per ml of tissue extract.

The term “no microscopy step” as used herein refers to the evaluation ofa method for Trichinella detection, wherein no microscope or microscopicevaluation, in particular a manual microscopic evaluation, is necessaryfor the evaluation of the method according to the invention.

The term “meat inspection” or “inspection before slaughter and afterslaughter,” as used herein, refers to a process intended to ensure thatthe meat of certain species of animals is put into commerce as food onlyif it is considered fit for consumption by humans. This investigation isan integral part of measures to ensure meat hygiene. The examination isusually carried out by official veterinarians or meat inspectors in twostages, namely the examination of the animal and the examination of themeat.

In a preferred embodiment, the term “detection limit” as used hereinindicates the least amount of a substance (antigen) that can bedistinguished from the absence of that substance with a specificprobability. Alternatively, the term “detection limit” may refer to theconcentration of an antigen in a solution, where the measured value isgreater than the associated uncertainty. The detection limit can bearbitrarily defined as 3 standard deviations (SD) away from the zeroconcentration.

In further preferred embodiments, the method of the invention isperformed by means of an immunoassay, more preferably by an ELISA, lineblot assay, Western blot assay, bead-based assay, lateral flow assay,vertical filtration assay, or 3D immunofiltration assay.

In a preferred embodiment, the term “immunoassay” as used herein refersto the detection or quantification of an analyte—such as a given antigenof Trichinella—comprising an immune reaction between an antibody and theantigen. In the context of the invention, the analyte to be detected orquantified may comprise a peptide, a post-translationally modifiedpeptide, preferably a glycoprotein, a sugar, a lipid, a nucleic acidand/or another molecule of Trichinella.

In a preferred embodiment, the term “ELISA” as used herein stands forEnzyme-linked Immunosorbent Assay and refers to an antibody-baseddetection method (assay). The ELISA belongs to the group of immunoassaymethods based on an enzymatic color reaction and thus belongs to theenzymatic immunoadsorption methods (EIA). Preferred embodiments includedirect ELISA, indirect ELISA, direct sandwich ELISA, bridging ELISA,indirect sandwich ELISA, and competitive ELISA. A person skilled in theart is familiar with the stated form and other forms and derivatives ofELISA.

In a preferred embodiment, the term “lateral flow assay” as used herein(English for “lateral flow test”) is a biochemical method for thequalitative detection of materials/substances/antigens with antibodies.The lateral flow assay is a combination of thin layer chromatography andimmunostaining. The lateral flow assay can be used in the form of a teststrip.

In a preferred embodiment, the term “vertical filtration assay” as usedherein is based on contacting ligands/antigens to be tested with amembrane on which captor antibodies are immobilized. This is followed bya washing process to remove weakly bound molecules and detection ofbound ligands. The difference between lateral flow assay and verticalfiltration assay is the lateral and vertical flow of the test fluid.Vertical flow technology has several advantages over the lateral flowassay, for example shorter assay times may occur.

In a preferred embodiment, the term “3D immunofiltration assay” as usedherein refers to an immunological rapid assay in flow-through assayformat based on the same biochemical principle of analyte recognition byreceptor structures as the lateral flow assay. The difference is thatthe addition of the sample/antigen, conjugate and additional washsolutions occurs sequentially on a three-dimensional porous shaped bodyon which captor antibodies are immobilized. All solutions and theirconstituents, such as analytes/antigens and detection reagents, flowinto the depth of the shaped body by means of through-flow. By utilizingenrichment effects, it is possible to increase detection limits.

In a preferred embodiment, the term “line blot” refers to a test stripto which at least one purified antigen is applied by printing on aprecisely predetermined position on the strip. The preparation of suchtest strips is described in the prior art. If antibodies are present inthe sample, its complex can be detected colorimetrically with theantigen. The reading is done visually or by intensity measurement ofresulting bands. The test strip may contain a positive control in theform of a band that appears when the strip has been incubated withserum, irrespective of whether or not it contains the analyte to bedetected.

In a preferred embodiment, the term “bead-based assay” refers to a testin which the carrier used is a bead, preferably a magnetic bead, onwhich a reagent for the detection, preferably an antibody against anantigen of Trichinella, is immobilized. Detection of theantibody-antigen complex can be carried out by chemiluminescence,preferably by means of a second antibody which carries a signal moleculedetectable by chemiluminescence. The bead is preferably chemically inertand comprises slow-reacting carbohydrates.

In preferred embodiments of the method according to the invention, thismethod comprises the following steps:

(a) providing a detection carrier comprising a first antibody againstone or more antigens of Trichinella;

(b) contacting the detection carrier with the sample;

(c) (i) contacting the detection carrier and any sample material boundthereto with a second antibody against one or more antigens ofTrichinella, wherein the second antibody is bound to a signal moleculeand wherein the presence of a signal of the signal molecule indicatesthe presence of Trichinella in the sample; or(c) (ii) contacting the detection carrier and, if applicable, any samplematerial bound thereto with one or more antigens of Trichinella, whereinthe antigens of (c) (ii) are bound to a signal molecule and configuredso as to dissolve binding of the antigens from (a) to the first antibodyby competitive displacement, wherein the presence of a signal of thesignal molecule indicates the presence of Trichinella in the sample.

In further preferred embodiments, in each case a washing step takesplace after the contacting steps (b), (c) (i) and (c) (ii).

Furthermore, in preferred embodiments of the method, of use and of thekit, the signal molecule can be observed using analytical techniquessuch as fluorescence measurement, chemiluminescence measurement,radioactivity measurement, electron spin resonance measurement,ultraviolet/visible absorption spectroscopy, mass spectrometry, nuclearmagnetic resonance, magnetic resonance and electrochemical measurementmethods.

Suitable antigens of Trichinella are known from the state of the art.Preferably, the antigen is tyvelose.

In preferred embodiments, the first and second antibodies are directedagainst different epitopes of the same antigen.

In further preferred embodiments, the first and/or second antibody isselected from the group consisting of an antibody which is directedagainst a post-translational modification (possibly bound to a substrateprotein), preferably a molecule comprising tyvelose, an antibody whichis directed against an excretory-secretory (E/S) antigen of Trichinella,and an antibody prepared using a lysate of Trichinella spiralis.

The term “antibody” as used herein refers to proteins from the class ofglobulins that are formed in vertebrates in response to certainsubstances called antigens. Antibodies are components of the immunesystem. Antibodies are produced by a class of white blood cells called Blymphocytes. They can be differentiated using different classes, namelyimmunoglobulin A, immunoglobulin D, immunoglobulin E, immunoglobulin G,immunoglobulin M, immunoglobulin W, and immunoglobulin Y. In preferredembodiments, the first and/or the second antibody is/are immunoglobulinG.

In preferred embodiments, the antibodies used are selected from thegroup consisting of an antibody comprising a VH sequence according toSEQ ID NO: 1 and a VL sequence according to SEQ ID NO: 2, an antibodycomprising a VH sequence according to SEQ ID NO: 3 and a VL sequenceaccording to SEQ ID NO: 4, antibody 18H1 (IgG2a), which binds tyveloseand is described in [11], and variants of these.

The term “variant” as used herein refers to antibodies and VH and VLsequences that possess at least 70%, at least 75%, at least 80%, atleast 85%, at least 90%, at least 95%, at least 97%, or at least 99%homology with the reference antibody or with the reference sequence.Preferably, only those variants are used which have biological activity.“Biological activity” as used in this context means, in particular, thatthe corresponding peptides have at least 30%, at least 40%, at least50%, at least 60%, at least 70%, at least 80%, at least 90%, at least95% of the specific binding activity of their reference antibody or ofthe reference sequence. Functional fragments or derivatives ofantibodies or variants thereof, for example Fab, F (ab′), Fr, ScTv anddAb or aptamers with corresponding binding activity, can be used.

In a preferred embodiment of the method according to the invention,comminution of the tissue extract sample is carried out exclusivelymechanically. In other words, in this embodiment there is no comminutionstep that is carried out chemically and/or enzymatically by molecules orcompounds externally added to the process. In other preferredembodiments, no additional external chemical and/or enzymatic moleculesare added to the method in an amount such that the proteolytic activityachieves more than four times, more than three times or more than twicethe background proteolytic activity.

In a further preferred embodiment of the process according to theinvention, at least 30%, at least 35%, at least 40%, at least 45%, atleast 50%, at least 55%, at least 60%, at least 65%, at least 70%, atleast 75%, at least 80%, at least 85%, at least 90%, at least 95%, atleast 97% or at least 99% of all protease cleavage sites are not cleavedin the tissue extract sample. These proteases possess a hydrolyticactivity with regard to peptide bonds and belong to EC class 3.4.

In other preferred embodiments of the process according to theinvention, at least 30%, at least 35%, at least 40%, at least 45%, atleast 50%, at least 55%, at least 60%, at least 65%, at least 70%, atleast 75%, at least 80%, at least 85%, at least 90%, at least 95%, atleast 97% or at least 99% cleavage sites of pepsin, chymosin, cathepsinE, papain, cathepsin K, caspase, calpain, scytalidoglutamic peptidase,thermolysin, collagenases, carboxypeptidase A and B, chymotrypsin,plasmin, thrombin, trypsin, granzymes and/or kallikrein are not cleavedin the tissue extract sample.

In a further preferred embodiment of the process according to theinvention, at least 30%, at least 35%, at least 40%, at least 45%, atleast 50%, at least 55%, at least 60%, at least 65%, at least 70%, atleast 75%, at least 80%, at least 85%, at least 90%, at least 95%, atleast 97% or at least 99% cleavage sites of pepsin, chymosin,chymotrypsin and/or trypsin are not cleaved in the tissue extractsample. In particular, in the tissue extract sample, at least 30%, atleast 35%, at least 40%, at least 45%, at least 50%, at least 55%, atleast 60%, at least 65%, at least 70%, at least 75%, at least 80%, atleast 85%, at least 90%, at least 95%, at least 97% or at least 99%cleavage sites of pepsin are not cleaved.

The cleavage sites of the above peptidases are sufficiently known fromthe state of the art, for examplehttps://web.expasy.org/peptide_cutter/peptidecutter_enzymes.html#Peps,and are hereby incorporated in the description by reference.

The identity/homology of nucleic acid or amino acid sequences isdetermined by sequence comparison. This sequence comparison is based onthe BLAST algorithm established in the prior art and commonly used(compare [12] and [13]) and is principally achieved by assigning similarsequences of nucleotides or amino acids in the nucleic acid or aminoacid sequences to one another. A tabular assignment of the relevantpositions is referred to as alignment. Another algorithm available inthe prior art is the FASTA algorithm. Sequence comparisons (alignments),in particular multiple sequence comparisons, are created with computerprograms. Frequently used, for example, are the Clustal series (see, forexample, [14]), T-Coffee (see, for example, [15]) or programs based onthese programs or algorithms. Furthermore, sequence comparisons(alignments) are possible using the computer program Vector NTI® Suite10.3 (Invitrogen Corporation, 1600 Faraday Avenue, Carlsbad, Calif.,USA) with the predetermined default parameters; the AlignX module ofthis program for sequence comparisons is based on ClustalW.

Such a comparison also allows a statement about the similarity of thecompared sequences to each other. It is usually given in percentidentity, that is, the proportion of identical nucleotides or amino acidradicals at the same position or in positions corresponding to oneanother in an alignment. The broader term of homology takes preservedamino acid substitutions in amino acid sequences into consideration, inother words amino acids with similar chemical activity, since theseusually perform similar chemical activities within the protein.Therefore, the similarity of the sequences compared may also be statedas percent homology or percent similarity. Identity and/or homologyinformation can be made about whole polypeptides or genes or only aboutindividual regions. Homologous or identical regions of different nucleicacid or amino acid sequences are therefore defined by matches in thesequences. Such areas often have identical functions. They can be smalland comprise only a few nucleotides or amino acids. Often, such smallregions perform essential functions for the overall activity of theprotein. It may therefore be useful to relate sequence matches only toindividual, possibly small areas. Unless otherwise indicated, however,identity or homology information in the present application refers tothe total length of the nucleic acid or amino acid sequence indicated.

The phrase “configured so as to dissolve binding of the antigens to theantibody by competitive displacement,” as used herein, refers toantigens that compete with already bound antigens for binding to a givenantibody. The competitive antigens are structurally similar to eachother and therefore the antigens can be referred to as structuralanalogs. The displacing antigen may have a higher affinity for theantibody than the displaced antigen and/or the displacing antigen ispresent in higher concentration than the displaced antigen.

The term “antigen” as used herein preferably refers to substances towhich antibodies and certain lymphocyte receptors can specifically bind.Antigens can be proteins, but also glycoproteins, carbohydrates, lipidsor other substances. In the present case, the antigens are preferablyproteins or post-translationally modified proteins.

In a second aspect, the present invention is directed at use of adetection system for the detection of Trichinella, preferably for meatinspection, wherein the detection system comprises (a) a detectioncarrier comprising a first antibody against one or more antigens ofTrichinella, and (b) (i) a second antibody against one or more antigensof Trichinella, wherein the second antibody is bound to a signalmolecule, or (b) (ii) comprises one or more antigens of Trichinellabound to a signal molecule, wherein the antigens from (b) (ii) areconfigured so as to dissolve binding of the antigens of (a) to the firstantibody by competitive displacement.

The term “detection system” as used herein preferably comprises (a) adetection carrier as defined herein and (b) an antigen or antibody boundto a signal molecule. The components of (a) and (b) act synergisticallyin such a way that addition of an antigen to be examined results in abinding complex of all the molecules involved, which allows detection ofthe antigen to be investigated in a sample by way of the presence of asignal.

The term “detection carrier” as used herein preferably refers to asubstance to which an antibody against one or more antigens ofTrichinella is bound. The carrier can be a solid article such as aslide, a 6-well, 12-well, 96-well or 384-well plate, a membrane,preferably a nitrocellulose membrane, a filter material, a bead,preferably a magnetic bead, or a thin-layer chromatography material.Alternatively, the detection carrier may also be a bead, the diameter ofsuch a bead preferably being smaller than 1000 μm, 800 μm, 600 μm, 400μm, 200 μm, 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20μm, 10 μm or 5 μm. The detection carrier can preferably compriseplastic, glass, metal or a combination thereof.

In a third aspect, the present invention is directed at a kit comprising(a) a detection carrier comprising a first antibody against one or moreantigens of Trichinella, and (b) (i) a second antibody against one ormore antigens of Trichinella, wherein the second antibody is bound to asignal molecule, or (b) (ii) comprises one or more antigens ofTrichinella bound to a signal molecule, wherein the antigens of (b) (ii)are configured so as to dissolve binding of the antigens from (a) to thefirst antibody by competitive displacement.

The term “kit” as used herein preferably refers to a package providedwith containers (e.g. bottles, plates, tubes, cups, etc.), eachcontaining a specific material, in the present case especially adetection carrier as defined herein, and an antigen or antibody bound toa signal molecule. Preferably, the kit is accompanied by instructionsfor use of the aforementioned material. The instruction manual may bewritten or printed on paper or another medium, or may be provided in theform of electronic media such as magnetic tape, a computer-readable diskor tape, or CD-ROM. The kit preferably contains a positive control,preferably with an antigen to be detected and/or samples for calibrationor creation of a calibration curve.

In a preferred embodiment, the kit furthermore comprises a descriptionof a method according to the invention for detecting Trichinella.

FIG. 1 shows the E/S proteins of an encapsulated Trichinella spiralislarva. The E/S proteins are secreted by the larva into the capsule andinto the surrounding tissue. By comminuting the tissue, the proteins arereleased into the sample material.

FIG. 2 shows an incubation schematic of the Trichinella antigen captureELISA. 1) Anti-Trichinella Ab C9 immobilized on a microtiter plate, 2)sample (Trichinella antigen), 3) Biotinylated detection Ab B7 bound tostreptavidin with PolyHRP80.

FIG. 3 shows the particle size determination of pork shredded using theGM200 knife mill from Retsch. 100×1 g of diaphragm muscle werecomminuted with 200 ml of PBS in the GM200 at 10,000 rpm for 6 and 9min, respectively. The particle size is plotted against Q3 [%] (volumepercent). In each case, about 60 million particles were measured. A)Particle size determination using the Camsizer® XT. n=0.3 B) Particlesize determination using the HORIBA LA-960. n=1.

FIG. 4 shows a recorded image of individual meat particles during themeasurement using the Camsizer® XT. The shape is generally not round,but rather very fibrous and elongated, so that the width to length ratiodecreases.

FIG. 5 shows the test of the antibodies anti-[TRISP][B7] andanti-[TRISP][C9] for the detection of Trichinella. A)-D) T. spiralisIIFT (Indirect Immunofluorescence Test): Ab B7 and Ab C9 were incubatedat a concentration of 2 μg/ml. A)+B) Incubation with Ab B7: The Ab showsa clear reaction both in the case of the encapsulated Trichinella larvain cross-section and in the case of the muscle larva; C)+D) Incubationwith Ab C9: Like B7, the Ab shows a clear reaction both in the case ofthe encapsulated Trichinella larva in cross section and in the case ofthe muscle larva; E) Western blot: 5 μg of T. spiralis lysate areapplied in each case, and the incubation was carried out with the Ab B7and the Ab C9 (concentration 0.4 μg/ml).

FIG. 6 shows the test of the specificity of the antibodiesanti-TRISP[B7] and anti-TRISP[C9] by means of Western blot. Track 1)Trypanosoma cruzi, 2) Ascaris suum, 3) Strongyloides ratti, 4) Toxocaracati, 5) Toxoplasma gondii, 6) Salmonella typhimurium, 7) Salmonellacholerasuis strain A, 8) Salmonella cholerasuis strain B, 9) Salmonellatyphisuis, 10) Trichuris suis, 11) Trichinella spiralis. Applied: 5 μglysate each. Incubation with Ab B7 (concentration 0.4 μg/ml, 2 h).

FIG. 7 shows results of the T. spiralis antigen capture ELISA. A)Detection limit of the T. spiralis antigen capture ELISA. Variousconcentrations of E/S antigen are plotted against the O.D. B) T.spiralis antigen capture ELISA with E/S antigen, positive and negativetissue extract as the sample material. The positive tissue extractsample contained approximately 100 encapsulated Trichinella larvae.Dashed line: Cut-off.

FIG. 8 shows results of the T. spiralis antigen capture ELISA withpositive and negative tissue extract as the sample material. Thepositive tissue extract contained approximately 100 encapsulatedTrichinella larvae. The sample material was comminuted for 3, 6, and 9min. Dashed line: Cut-off. n=3.

FIG. 9 shows an incubation schematic of the manually incubatedTrichinella chemiluminescence immunoassay. 1) Anti-Trichinella captureAb 18H1 immobilized on a magnetic bead, 2) Sample (Trichinella antigen),3) Biotinylated anti-Trichinella detection Ab B7, 4)extravidin/acridinium reagent.

FIG. 10 shows the processing schematic of the chemiluminescence analyzerdevice for the automated Trichinella chemiluminescence immunoassay. Themagnetic bar transports the beads immobilized with anti-Trichinella Ab18H1 successively into reaction vessels filled with various reagents.The sample and trigger B are added automatically.

FIG. 11 shows results of the automated Trichinella chemiluminescenceimmunoassay. The particle sizes of the comminuted pork were measuredafter 2, 3, 5, and 7 min using the particle size analyzer LA-960 fromHORIBA. In addition, meat samples—negative and mixed with 6, 13, and 30Trichinella larvae—were comminuted between 2 and 7 min. The resultingtissue extract was incubated using the automated CLIA. The results aregiven in relative light units (RLU).

SEQUENCES

In the present invention, various peptide sequences are disclosed, inparticular

SEQ ID NO: 1 (Anti-[TRISP][B7]VH):AVTLDESGGGLQTPRGGLSLVCKASGYTFSSHNMAWVRQAPGKGLEFVAGISNTGSFTLYGAAVKGRATISRDNGQSTVRLQLNNLRAEDTGTYYCAKHA GVGLYSIDAWGHGTEVIVSSSEQ ID NO: 2 (Anti-[TRISP][B7]VL):ALTQPSSVSANLGGTVKITCSGGTSDYGWYQQKAPGSAPVTLIYDNTNRPSDIPSRFSGSLSGSTNTLTITGVQAEDEAVYFCGSADRTYAGVEGAGTTL TVLSEQ ID NO: 3 (ANTI-[TRISP][C9]VH):AVTLDESGGGLQTPGGALSLVCKASGFSISSYSMQWVRQAPGKGLEWVAGIYYDGNTWYAPAVKGRATISRDNGQSTVRLRLNNLRAEDTATYFCAKYAG GYSIDAWGHGTEVIVSSSEQ ID NO: 4 (ANTI-[TRISP][C9]VL):ALTQPSSVSANPGETVKITCSGSSGSYGWYQQKSPGSGPVTVIYYNDKRPSDIPSRFSGSASGSTATLTITGVQAEDEAVYFCGGYDSSTYVGIFGAGTT LTVLSEQ ID NO: 5 (ANTI-[TRISP][18H1]VH):QVQLKESGPGLVQPSQTLSLTCTVSGLSLTSNSVGWIRQPPGKGLEWMGIIWSNGGTDYNSAIKSRLSISRDTSKSQVFLKMHSLQTEDTAMYFCARGPYYGSYRLGYFDYWGQGVMVTVSS SEQ ID NO: 6 (ANTI-[TRISP][18H1]VL):DVVMTQSPSSLAVSAGETVTLNCQSSQSLLYSGTQNNYLAWYQQKPGQSPKLLISWASTRQSGVPLRFIGSGSGTDFTLTITSVQAEDLAIYYCQQFYDT PLTFGSGTKLEIK

The present invention is further illustrated by the non-limitingexamples, from which further features, embodiments, aspects, andadvantages of the present invention can be derived.

EXAMPLES Example 1: Material and Methods

Material

Material Name Product number Manufacturer Equipment AutomatedPerkinElmer Chemiluminescent Analyzer SuperFlex Biometra WT 15 042-400Biometra shaker Centro XS³ LB 960 Berthold Technologies MicroplateLuminometer GM 200 Accessories: 03 045 0050 Retsch Grinding container,stainless steel GM 200 Accessories: Knife, 02 446 0057 Retsch serratedHydroFlex ™ Microplate Tecan Washer, Magnetic Beads Incubator WTB BINDERKnife mill GRINDOMIX GM 20 253 0001 Retsch 200 MTS 2/4 digitalmicrotiter 3208001 IKA shaker Novex Mini Cell Invitrogen Photometer:Sunrise ™ Tecan Power Pac HV Bio-Rad Table centrifuge: Biofuge HeraeusFresco Washer Columbus Tecan XCell SureLock ™ Mini-Cell ThermoFisherScientific Electrophoresis System Zentrifuge Avanti ® J-E BeckmanCoulter (Rotor: JA-10) Tilt/roll mixer IKA Consumables iD PAGE Gel,4-20% ID-PA4201-015 Eurogentec Dynabeads ™ M-280 Tosyl- 14203ThermoFisher Scientific activated Microtiter plate LockWell 446475-EURThermoFisher Scientific Maxisorb Nitrocellulose membrane 11306 SartoriusNunc ™ F96 MicroWell ™ 136101 ThermoFisher Scientific Polystyrene Plate,white Reagent Cartridges PerkinElmer (SuperFlex) Protective caps formagnetic PerkinElmer rod (SuperFlex) Media, Ammonium sulphateSigma-Aldrich Solutions, solution and Buffers (3M) Antibody dilutionbuffer EUROIMMUN Blocking buffer ELISA EUROIMMUN Chromogen/substrate ZE1200-0112 T EUROIMMUN solution ELISA TMB/H2O2 Enzyme Conjugate AlkalineAE 142 1030 EUROIMMUN Phosphatase-labeled Anti- Human-IgG (Goat)Extravidin/acridinium EUROIMMUN reagent Beads coating buffer EUROIMMUNPBS ZF 1100-1000 T EUROIMMUN PBS + 0.05% Tween-20 ZF 1110-0102 TEUROIMMUN (PBST) StabilCoat ® Plus SC01 Surmodics Stop solution ELISA(0.5M ZE 1210-0112 T EUROIMMUN sulfuric acid) Substrate Solution BlotNitro ZW 1020-0130 T EUROIMMUN Blue Tetrazolium Chloride/5-Bromo-4-chloro-3-indolyl Phosphate (NBT/BCIP) Trigger A for CLIAEUROIMMUN Trigger B for CLIA EUROIMMUN Tris buffer (1M) #1218 GerbuBiotechnik Wash Buffer Blot ZW 1100-1005 T EUROIMMUN Wash Buffer ELISAZE 1120-1000 T EUROIMMUN Wash Buffer Plus Blot ZW 1110-1005 EUROIMMUNReady-to-use Color Prestained Protein P7712S New England BioLabsSolutions and Standard, Broad Range (11- Kits 245 kDa) NuPAGE ® LDSSample Buffer ThermoFisher Scientific (4X) NuPAGE ™ MOPS SDS NP0001ThermoFisher Scientific Running Buffer (20X) Antigens Ascaris suum Prof.Dr. Christina Strube, University of Veterinary Medicine Hanover, DESalmonella typhimurium Prof. Dr. Michael Salmonella cholerasuis strain AHensel Salmonella cholerasuis strain B microbiology Salmonella typhisuisUniversity of Osnabrück Strongyloides ratti EUROIMMUN Toxocara catiEUROIMMUN Toxoplasma gondii BA110VS Virion/Serion Trichinella spiralisE/S EUROIMMUN antigen Trichinella spiralis lysate EUROIMMUN Trichurissuis Prof. Dr. Eva Liebau Molecular Physiology University of MünsterTrypanosoma cruzi Virion/Serion Antibodies Anti-[TRISP][B7] EUROIMMUNAnti-[TRISP][C9] EUROIMMUN Anti-[TRISP][18H1] EUROIMMUN/Prof. Dr. JudithAppleton, Cornell University, Ithaca, USA Other EZ-Link ™ NHS-PEG12biotin 21312 ThermoFisher Scientific Materials IIFT Trichinella spiralisEUROIMMUN “Encapsulated Larva” IIFT Trichinella spiralis EUROIMMUN“Muscle larva” Pork samples mixed with a [German] Federal defined numberof Institute for Risk Trichinella muscle larvae Assessment (BfR) Porkdiaphragm muscles Butcher Prösch, Krummesse Spectra ™ Multicolor BroadThermoFisher Scientific Range Protein Ladder Streptavidin-PolyHRP80,#SP80C SDT (Stereospecific stock 1 mg/ml solution DetectionTechnologies) Trichinous pork infected [German]Federal with 20 to 50larvae per Institute for Risk gram Assessment (BfR) Zeba ™ SpinDesalting 87772 ThermoFisher Scientific Columns, 40K MWCO, 10 mLMethodsMethod for Obtaining Tissue Extract Samples

In the present detection method, the meat is not supposed to beenzymatically digested, but rather mechanically comminuted. In thisregard, a particle size of the meat of <200 μm is to be achieved. Thelarvae, together with the collagen capsule, are approx. 200-600 μm longand 200-300 μm wide, so that with a desired particle size of <200 μm, itcan be assumed that the encapsulated Trichinella larvae would have to becaught at least once by the cutting knife of the comminution device. Thecapsule contains numerous E/S proteins, which are released duringcomminution and then freely present in the sample material (FIG. 1). Thesomatic proteins can be additionally detected by the comminution of thelarva.

Following comminution, antigen detection is performed in the form of anantigen capture ELISA or a manually incubated or automatedchemiluminescence immunoassay.

Sample Preparation

At the slaughterhouse, removal of about 5 g of meat per animal is usual.As a standard procedure, the sample is taken from the muscular part ofthe diaphragm of an animal that has already been killed. For theTrichina inspection, 1 g of sample material is used per pig. For otherparts of the body, such as the tongue or intercostal muscles, the amountof the sample may vary. As a rule, 100 pig samples are pooled, resultingin a sample volume of 100×1 g. The sample is cooled down to 4° C.

Comminution of the Meat Samples

The sample material (100×1 g meat) was added to the grinding bowl of acrusher, which was pre-chilled to 4° C. The knife mill Grindomix GM 200from Retsch was used for this purpose. The comminution principle isbased on cutting of the sample. The knife mill can be equipped with aserrated knife, so that even fibrous materials such as muscle tissue canbe finely comminuted. 200 ml of PBS at a temperature of 4° C. were addedto the sample. At 10,000 rpm and thus maximum power, the sample materialwas comminuted as indicated, e.g. for 9 min.

In order to check whether comminution of the meat was successful, aparticle size measurement was carried out using the Camsizer® XT fromRetsch and the LA-960 from HORIBA. The LA-960 is based on the functionalprinciple of static laser scattering, whereas the Camsizer® XT is basedon dynamic image analysis. In each case, three meat samples were takenafter 6 minutes or 9 minutes, and measured directly afterwards. Anaverage of 60 million particles were measured. The particle size wasmeasured in x_(c min) and defined according to DIN 66141 as follows:Shortest particle diameter of the measurements of the maximum diameterwithin a particle projection (English: particle diameter which is theshortest chord of the measured set of maximum chords of a particleprojection) [8].

Centrifugation

After comminution, 1 ml to 15 ml of sample were taken from the grindingbowl using a pipette. This was followed by sedimentation of the coarseparticles in the sample by centrifugation at 5,000×g and 4° C. for 10minutes. The supernatant after sedimentation is the sample material forsubsequent antigen detection and is referred to as a tissue extract.

Method of detecting Trichinella spiralis from tissue extract samplesProduction of the sample material

T. spiralis Lysate

T. spiralis muscle larvae (ML) were provided by Justyna Bieri from theWitold Stefariski Institute PAS in Warsaw. 120,000 ml were centrifugedfor 10 min at 16,000×g and room temperature (RT), so that all larvaewere pelleted. The supernatant was discarded and 1 ml of PBS was added.The larvae were exposed to five cycles of freezing and thawing, and thencomminuted using a hand-held homogenizer. Finally, the samples weretreated with ultrasound: 20 cycles of 5 sec each at medium strength and5 sec rest periods between treatments, on ice. This was followed by 20minute centrifugation at 16,000×g and 4° C. The supernatant representsthe antigen T. spiralis lysate.

E/S Antigen

The T. spiralis ML E/S antigen was provided by Justyna Bień from theWitold Stefański Institute PAS in Warsaw.

Production of Antibodies

The antibodies used for the antigen-capture ELISA were prepared using aphage display method [9]. The sequences of the heavy and light chainvariable regions (VH and VL) of the two antibodies anti-[TRISP][B7] andanti-[TRISP][C9] (abbreviated as Ab B7 and Ab C9) are as follows:

Anti-[TRISP][B7]VH (SEQ ID NO: 1):AVTLDESGGGLQTPRGGLSLVCKASGYFSSHNMAWVRQAPGKGLEFVAGISNTGSFTLYGAAVKGRATISRDNGQSTVRLQLNNLRAEDTGTYYCAKHA GVGLYSIDAWGHGTEVIVSSAnti-[TRISP][B7]VL (SEQ ID NO: 2):ALTQPSSVSANLGGTVKITCSGGTSDYGWYQQKAPGSAPVTLIYDNTNRPSDIPSRFSGSLSGSTNTLTITGVQAEDEAVYFCGSADRTYAGVEGAGTTL TVLANTI-[TRISP][C9]VH (SEQ ID NO: 3):AVTLDESGGGLQTPGGALSLVCKASGFSISSYSMQWVRQAPGKGLEWVAGIYYDGNTWYAPAVKGRATISRDNGQSTVRLRLNNLRAEDTATYFCAKYAG GYSIDAWGHGTEVIVSSANTI-[TRISP][C9]VL (SEQ ID NO: 4):ALTQPSSVSANPGETVKITCSGSSGSYGWYQQKSPGSGPVTVIYYNDKRPSDIPSRFSGSASGSTATLTITGVQAEDEAVYFCGGYDSSTYVGIFGAGTT LTVLBiotinylation of Antibody Anti-[TRISP][B7]

The Ab B7 was incubated, for antigen-capture ELISA, using EZ-Link™NHS-PEG12-biotin in a 20-times molar excess, for one hour at roomtemperature, on the rotary shaker. To remove excess biotin, the antibody(Ab) was purified according to the manufacturer's instructions, by wayof a size exclusion chromatography column (Zeba™ Spin DesaltingColumns).

SDS PAGE and Western Blot Analysis

For SDS PAGE, in each case 5 μg of T. spiralis lysate or lysate fromTrypanosoma cruzi, Ascaris suum, Strongyloides ratti, Toxocara cati,Toxoplasma gondii, Salmonella typhimurium, Salmonella cholerasuis strainA, Salmonella cholerasuis strain B, Salmonella typhisuis, and Trichurissuis were loaded onto a polyacrylamide gel, and electrophoresis wasperformed at 175V in MOPS buffer for 50 min. Transfer to anitrocellulose membrane took place for 60 min at 400 mA, in transferbuffer. The membrane was incubated for blocking on the rocker shaker, inWash Buffer Plus, for 30 min. Subsequently, antibodies B7 and C9 in WashBuffer Plus were applied at a concentration of 0.4 μg/ml, and incubatedovernight on the rocker shaker. After washing with washing buffer, themembrane was incubated with the enzyme conjugate “AlkalinePhosphatase-labeled Anti-Human IgG” from EUROIMMUN, diluted in WashBuffer Plus. Finally, after another washing step, the substrate solution(NBT/BCIP) was applied and incubated until a clear color change wasseen.

Indirect Immunofluorescence Test

In order to examine which structures bind the developed antibodies, anindirect immunofluorescence test for T. spiralis was developed. TheBIOCHIPS were loaded with frozen sections of T. spiralis muscle larvaeand encapsulated larvae. Incubation and microscopy were carried outfollowing the instructions of the EUROIMMUN Anti-Schistosoma MansoniIIFT (P/N FI 2300-1005 G). As a sample, the antibodies B7 and C9 wereapplied to the BIOCHIPS at a concentration of 2 μg/ml.

Antigen Detection by Means of Antigen Capture ELISA

For antigen detection, an enzyme-linked immunosorbent assay (ELISA) wasused as the detection method. A 96-well microtiter plate was coated with0.25 μg/ml antibody C9 in PBS overnight at 4° C. The next day, themicrotiter plate was washed once with PBST (PBS+0.05% Tween-20), blockedwith blocking buffer for 2 hours, and then dried for 2 hours.

For detection of the antigens bound to Ab C9, the Ab B7, at aconcentration of 0.05 μg/ml, and streptavidin-polyHRP80, at aconcentration of 0.1 μg/ml, were mixed together in antibody dilutionbuffer and incubated overnight.

Incubation of the Samples

The incubation was carried out as in the schematic shown in FIG. 2. Assamples, the T. spiralis E/S antigen, at various concentrations (0-50ng/ml), and tissue extract samples in a volume of 100 μl were applied tothe microtiter plate. The incubation was carried out for one hour atroom temperature, on a rotary shaker. The “positive” tissue extractsample was prepared in that before comminution, trichinous pork wasadded to negative diaphragm tissue, so that there were approximately 100encapsulated Trichinella larvae in the sample.

After washing with washing buffer six times, the 100 μl volume conjugatewas also incubated for one hour at room temperature, on a rotary shaker.It was then washed again six times and the substrate was applied. After15 min, the reaction was stopped with stop solution, and the opticaldensity (O.D.) of the samples was determined using a photometer at awavelength of 450 nm.

Example 2: Results

Comminution of the Meat Samples

Immediately following comminution of the pork using the GM200 knifemill, particle size determination was carried out using the Camsizer® XTand the HORIBA LA-960. Sampling took place after 6 or 9 min,respectively. The results of the mass distribution can be seen in FIG.3, where the particle size [μm] is plotted against Q3 [%] in a diagram.Q3 is the percentage of particles that are smaller than x with referenceto the total volume. Since the two particle size measuring devices arebased on different measuring methods, the results differ.

The results of the measurement with the HORIBA LA-960 show that 95% ofthe particles are <26 μm and all particles are <100 μm. With theCamsizer® XT measurement, 95% of the particles are <300 μm. Only 70% ofthe meat particles are <100 μm. FIG. 4 shows, as an example, what shapethe meat particles have. Due to the muscle fibers and myofibrils, thestructure is very fibrous, which clearly lowers the width to lengthratio.

In any case, the collagen capsule of a Trichinella larva, if present,would be statistically cut at least once by the knife, so that E/Sproteins can be released. These released proteins can be detected in thenext step, using an antigen-capture ELISA.

Preparation of the Sample Material and the Antibodies

To check whether the antibodies anti-[TRISP][B7] and anti-[TRISP][C9]are suitable for T. spiralis antigen detection, an indirectimmunofluorescence test (IIFT) and a Western blot were performed asfunctional tests. The results are shown in FIG. 5.

When antibody B7 is used, the cut capsule fluoresces most strongly (FIG.5 A). The larva inside and individual proteins on the capsule surfacealso fluoresce. The frozen section of the muscle larva shows a clearreaction at the outer membrane (FIG. 5 B).

In the cross-section of the encapsulated larva, the entire larvafluoresces most strongly when incubated with the Ab C9 (FIG. 5 C). Theindividual proteins on the capsule surface and the cut capsule fluoresceweakly. In the case of the muscle larva, not only does the outermembrane show a clear reaction, but the inside of the larva does also(FIG. 5 D).

In the Western blot, clear reactions for the antibodies B7 and C9 canalso be seen (FIG. 5 E). The two antibodies show an identical bandpattern. Strong bands occur at approximately 48, 50, 52, 60, 65, and 110kDa. The epitope bound by the antibodies seems to be present in severalproteins or glycoproteins, and this may have a positive effect on thedetection of very low-concentration Trichinella antigens in the samplematerial.

In order to check whether the antibodies bind exclusively to specificstructures of T. spiralis and not to other antigen structures of otherparasites and/or bacteria, a Western blot was performed. Lysates ofpathogens found in pigs were applied. The result can be seen in FIG. 6.The lysates tested possess no structures bound by Ab B7 or Ab C9. Afalse positive reaction can be excluded for these pathogens, with highprobability, in the later antigen capture ELISA.

Antigen Capture ELISA

For the functional test of the developed T. spiralis ELISA, variousconcentrations of E/S antigen were used in the test (FIG. 7 A). Thedetection limit, at a cutoff of 0.3 O.D., lies at approximately 6 ng/ml.

In FIG. 7 B, results of tissue extract samples prepared according to theprocedure described herein were shown. Both a positive sample,containing about 100 encapsulated larvae in the pork, and a negativesample were tested. The antigen capture ELISA shows a clear differenceof almost 2 O.D. between the positive and the negative tissue extractsample.

The T. spiralis antigen concentration in the tissue extract samplecorresponds to approximately 30 ng/ml E/S antigen. Consequently, 100comminuted encapsulated larvae release approximately that amount ofprotein into the meat juice, and this can be detected by the antigencapture ELISA.

Antigen-Capture ELISA with Differently Comminuted Sample Material

FIG. 8 shows the results of comminution, after 3, 6, and 9 min, ofpositive and negative tissue extract. It can be seen that the negativetissue extract without larvae in the sample material shows nosignificant reaction, since the O.D. in ELISA lies below the cut-off of0.3. The tissue extract that was produced from meat and containedapproximately 100 encapsulated T. spiralis larvae shows a clear reactionat >1.5 O.D. The effects resulting from the scope of comminution areconspicuous, since the reaction increases with an increasing comminutiontime. The O.D. in the case of the 9-minute comminution is 0.5 higherthan in the case of the 3-minute comminution.

The reaction in the ELISA is lower in the case of the sample materialwhich was comminuted for 3 minutes than after comminution for 9 minutes.Prolonged comminution of the sample material consequently results in ahigher amount of released T. spirolis antigen. During prolongedcomminution, it is likely that all encapsulated Trichinella larvae willbe caught at least once and, in general, multiple times by the cutterblade, so that more detectable antigens are available for ELISA in thesample, as compared with shortened comminution.

Example 3: Antigen Detection by Means of a Manually Incubated andAutomated Chemiluminescence Immunoassay

For the manually incubated and bead-based chemiluminescence immunoassay(CLIA), the capture antibodies were coupled to magnetic beads ratherthan to a microtiter plate. Tosyl-activated Dynabeads' were used forthis purpose. The hydrophobic polyurethane surface was activated withtosyl groups, which allowed the antibodies to be covalently bound to thebeads. 4 mg of the beads were equilibrated with 1 ml of a 1 M Trisbuffer. 30 mM Tris, 0.4 M ammonium sulfate, and 28 μg anti-[TRISP][18H1]antibody (abbreviated as Ab 18H1) were added to the equilibrated beads.The incubation was carried out overnight at 37° C., on a roller mixer.The next day, the beads were washed three times with 1 ml each ofStabilCoat® Plus, and then incubated overnight at 37° C., on the rollermixer, to block any remaining reactive functional groups. Afterblocking, the beads were taken up in fresh StabilCoat® Plus and storedat a concentration of 1 mg/ml at 4° C. until use.

The beads coated with 18H1 antibody were pipetted into a microtiterplate well (Nunc™ polystyrene plate) for the CLIA, at 10 μg each. 100 μlof the undiluted tissue extract sample were added, and incubated for 30min on a rotary shaker. After automated washing three times using theHydroFlex™ Microplate Washer, 100 μl of the biotinylated B7 antibody ata concentration of 0.1 μg/ml were incubated for 30 minutes on a rotaryshaker. This was followed by three times automated washing. For thechemiluminescence reaction, the extravidin/acridinium reagent, at aconcentration of 80 ng/ml and a volume of 100 μl, was added to the beadsand incubated for 15 min. After washing three times, the measurement wascarried out using the Centro XS³ microplate luminometer. The luminometerautomatically added 100 Cl of each of the triggers A and B to everybatch, to start the chemiluminescence reaction. The light emission wasmeasured at 425 nm wavelength for 1 sec and reported in Relative LightUnits (RLU). The incubation schematic of the manually incubated CLIA isshown in FIG. 9.

The automated and bead-based chemiluminescence immunoassay is based onthe structure of the manually incubated CLIA. The difference is that thetest is performed using an Automated Chemiluminescence Analyzer(SuperFlex, PerkinElmer). The beads are successively immersed in thevarious reagents by a magnetic rod. The magnetic rod is able to generatean electric field and can thereby pick up the beads, drop them, and mixthe reagents at a predefined interval.

For the automated CLIA, the tissue extract samples were loaded into thesample compartment of the analyzer. The reagent cartridges were filledas shown in FIG. 10. Per reaction, 10 μg of the beads coated with 18H1antibody were used. These were incubated with 100 μl of tissue extractsample and 100 μl of biotinylated anti-TRISP[B7] antibody at aconcentration of 0.25 μg/ml for 30 min. The beads were taken up with themagnetic bar after incubation, and washed 3 times in washing buffer(V=400 μl). This was followed by a 10-minute incubation with 100 μl of0.1 μg/ml extravidin/acridinium reagent. After being washed three times,the beads were added to 100 μl of Trigger A, and Trigger B (V=100 μl)was pipetted in by the analyzer to start the chemiluminescence reaction.The light emission was measured at 425 nm wavelength for 1 sec by theluminometer built into the analyzer, and reported in Relative LightUnits (RLU).

Results of the Manually Incubated Chemiluminescence Immunoassay (CLIA)Different concentrations of T. spiralis lysate samples were incubatedwith the manually incubated CLIA. The detection limit was 1 ng/ml T.spiralis lysate.

Results of the Automated Chemiluminescence Immunoassay (CLIA) Differentconcentrations of T. spiralis lysate samples were also incubated usingthe automated chemiluminescence immunoassay. The detection limit was 10μg/ml T. spiralis lysate. In addition to the meat samples infected withTrichinella, meat samples that were mixed with a defined amount ofTrichinella muscle larvae were also comminuted. They contained 3 to 30larvae. The detection limit of the automated CLIA was 3 larvae per 100grams of meat for the defined amount of muscle larvae.

FIG. 11 shows the correlation between particle size and the results ofCLIA of comminuted and Trichinella-positive tissue extract. It can beseen that the particle size of the meat decreases with an increasingcomminution time, whereas the reaction of the CLIA increases. Withprogressive comminution of the meat, and thus also of the larvae, moreTrichinella antigens are released. These can then be detected by theCLIA. The relative light units (RLU) also increase with an increasingnumber of larvae in the meat sample. The Trichinella-positive tissueextract from meat samples mixed with 30 larvae shows more than threetimes as high a reaction (150,000 RLU) than the tissue extract of 6larvae (50,000 RLU) after 6 min comminution.

The invention is described generically and generally herein. Each of thenarrower types and subgroups covered by the generic disclosure alsoforms part of the invention. This includes the general description ofthe invention with a reservation or negative restriction that removesevery object from a (sub)group, whether or not the cut-out object isspecifically cited here. Other embodiments are contained in thefollowing claims.

A person skilled in the art will readily appreciate that the presentinvention is well suited for accomplishing the tasks and achieving thestated advantages and goals connected with them. Furthermore, it will bereadily apparent to a person skilled in the art that varioussubstitutions and modifications can be made to the invention disclosedherein, without departing from the scope and spirit of the invention.The methods, uses, treatments, molecules, and kits described herein arerepresentative of preferred embodiments, which are exemplary and are notintended to restrict the scope of the invention. Changes therein andother uses will occur to persons skilled in the art, and these areincluded within the scope of the invention and defined by the scope ofthe claims. Listing or discussion of a previously published document inthis description should not necessarily be understood as proof that thedocument belongs to the prior art or is generally known.

The invention illustratively described herein can be suitably carriedout in the absence of any element or restrictions not specificallydisclosed herein. For example, the terms “comprising,” “including,”“containing,” etc., are read comprehensively and without restriction.Accordingly, the word “comprise” or variations such as “comprises” or“comprising” are to be understood as being implicit; i.e., for example,numbers that are given are included, but not excluded. In addition, theterms and expressions used herein have been used as expressions ofdescription and not of restriction, and there are no intentions torestrict such terms and expressions, so as to restrict any equivalentsof the features shown or described, or parts thereof. In other words,various modifications are possible within the scope of protection of theclaimed invention. This should be understood to mean that while thepresent invention has been specifically disclosed by means of exemplaryembodiments and optional features, which are disclosed herein,modifications and variations of the inventions disclosed herein can beused by persons skilled in the art, and that such modifications andvariations should be viewed as being within the scope of protection ofthis invention.

The contents of all documents and patent documents cited herein areincorporated by reference, in their entirety.

Abbreviations

Abbreviation English German μg microgram Mikrogramm μl microliterMikroliter German: AG antigen Antigen English: Ag German: AK antibodyAntikörper English: Ab CLIA Chemiluminescence ImmunoassayChemilumineszenz Immunassay E/S Excretory/SecretoryExkretorisch/Sekretorisch ELISA Enzyme-linked Immunosorbent Assay EUEuropean Union Europäische Union g gram Gramm IIFT indirectimmonofluorescence test Indirekter Immunfluoreszenztest l liter Liter mgmilligram Milligramm Min. minute Minute ml milliliter Milliliter MLmuscle larva Muskellarven NBL New Born Larva Neugeborene Larven NBT/BCIPnitro-blue tetrazolium chloride/5-bromo-4- Nitroblautetrazoliumchlorid/chloro-3-indolylophosphate p-toluidine salt 5-Brom-4-chlor-3-indolylphosphat Ng nanogram Nanogramm nm nanometer Nanometer O.D.Optical Density Optische Dichte rpm revolutions per minute Umdrehungenpro Minute RT room temperature Raumtemperatur Sek. second Sekunde SDSPAGE Sodium Dodecyl Sulfate Polyacrylamide Natriumdodecylsulfat- GelElectrophoresis Polyacrylamidgel- elektrophorese

LITERATURE

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The invention claimed is:
 1. A method of detecting Trichinella in atissue extract sample, said method comprising: comminuting the tissueextract sample from a human or animal to form particles, wherein atleast 90% of the particles have a diameter of 300 um or less; anddetecting an antigen of Trichinella in said tissue extract sample bydetecting the binding between an antibody to the antigen of Trichinellaand the antigen, wherein the antigen is at least one of tyvelose, anexcretory-secretory antigen, and a Trichinella spiralis lysate, whereinthe detecting comprises: contacting the particles with a first antibodythat is bound to one of beads, a membrane, a microtiter plate, a slide,a filter material, a thin layer chromatography material, and a teststrip, wherein the first antibody recognizes the antigen of Trichinella,contacting the particles with a second antibody that recognizes theantigen of Trichinella, the second antibody being bound to a signalmolecule; and detecting the antigen of Trichinella via the signalmolecule; wherein at least 40% of the cleavage sites of pepsin are notcleaved in the tissue extract sample.
 2. The method according to claim1, wherein the tissue extract sample is a mammalian sample.
 3. Themethod according to claim 1, wherein 90% of the particles in the tissueextract sample have a diameter of 250 μm or less.
 4. The methodaccording to claim 1, wherein the tissue extract sample is frommusculature of said human or animal.
 5. The method according to claim 1,wherein in the preparation of the tissue extract sample: (a) atemperature of 45° C. is not exceeded; and/or (b) no enzymatic and/orchemical cleavage of the tissue takes place.
 6. The method according toclaim 1, wherein the method (a) does not comprise a microscopy step; (b)is used in meat inspection; and/or (c) has a detection limit of <7 ngantigen per ml of tissue extract.
 7. The method according to claim 1,wherein the method is performed by an immunoassay.
 8. The methodaccording to claim 1, wherein Trichinella is Trichinella spiralis.
 9. Amethod of detecting Trichinella in a tissue extract sample, said methodcomprising: without enzymatically digesting the tissue extract sample,comminuting the tissue extract sample from a human or animal to formparticles, wherein at least 90% of the particles have a diameter of 300μm or less; and detecting an antigen of Trichinella in said tissueextract sample by detecting the binding between an antibody to theantigen of Trichinella and the antigen, wherein the antigen is at leastone of tyvelose, an excretory-secretory antigen, and a Trichinellaspiralis lysate, wherein the detecting comprises: contacting theparticles with a first antibody that is bound to one of beads, amembrane, a microtiter plate, a slide, a filter material, a thin layerchromatography material, and a test strip, wherein the first antibodyrecognizes the antigen of Trichinella; contacting the particles with asecond antibody that recognizes the antigen of Trichinella, the secondantibody being bound to a signal molecule; and detecting the antigen ofTrichinella via the signal molecule.